Core-drill.



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n FCO .l A c L P DI A Patented Mar. 18. 1919.

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FRANK MILLER, OF NEW YORK, N. Y.

CORE-DRILL.

Application nled April 12,

. To all 'whom t may concern:

Be it known that I, FRANK MILLER, a subject of the Crown of GreatBritain, (who has declared his intention of becoming a i citizen of theUnited States, residing at New York, in the county of ew York and Stateof New York, have invented a certain new and useful Improvement inCoreDri1lS, of which the following is a specification.

This invention relates to core drills, and in particular to a new formof cutting tool used in connection therewith and to the means forsupplying the abrading material and also forsupplying the uting materialto break oli and remove i? core.

The objects of my invention are to improve the construction of coredrills at present used; tov provide a double cutting bit having animproved form of shot feed, and

also to provide a new means for admitting the grouting material to breakolf the core and to raise the core to the surface.

Diiculties have been encountered in usin core drills of types previouslyknown in so t y strata or in strata alternately hard and soft for thereason that the core is subjected throughout its length to the abradingaction of the shot passing through the interior of the core barrel tothe cutting edge. The friction thus set up between the core and corebarrel is frequently suilicient to break olf the core wherever a seam ofsoft material occurs, and it is to overcome these objections that thepresent construction has been devised.

With these and other Aobjects in view, a new form of core drill has beendevised, a practical embodiment of whichis shown in the accompanyingdrawin .1

In the drawing annexed ereto and formina part ofthxs specification,

igure 4 1 is a vertical section taken through the lower section of myimproved core rill2 Fig. 2 1s a section taken on the line 2--2 of Fig.1,

3, is a section taken on the line 3 3 of g. 1, and

Fig. 4 shows a, slight modification of the` core arrel.

In the drawings, 1 designates the core barrel which is formed by asection of ritied pipe or any other section of tubing having a spiral orother protuberance extending throughout its len h, as more clearly shownin Fig. 3, at 2. e core barrel may also- Specification of LettersPatent.

Patented Mar. 18,1919.

1911. Serial No. 161,512.

be formed of heavy tubing in which grooves, preferably spiral, have beencut. The rificd or other pipin shown in the drawings is however well aapted to the purposes of this part for the reason that the protuberancesuch as that shown at 2, Fig. 3, acts as a support for the core barrelagainst the outer annulus or tubing 3 forming the outer cutting tool andholds it centrally thereof and provides a free and open passage for theshot or abrading material supplied to the cutting tool or bit formed bythe lower edges of the tubes 1 and 3. Surrounding the tubing or lpipe 1is the outer tube 3 against which the spiral groove or helix 2 or otherprotuberance rests throughout its length. The two tubes 1 and 3 at.their lower ends form the cutting or abrading tools of the drill. Thematerial which does the actual cutting or abradin which is commonlyreferred to as slot is supplied through the annular space between thetubes 1 and`3 to the lower ed es of the tubes where *The cutting takes pace The lower edges ofJthese tubes 1 and 3 may be supplied .vith anoblique cut as shown at 4 as is usual in this type of drill. y

The tubes 1 and 3 at their upper ends are secured to a core barrel plugor coupling 5 by means of threaded connections 6 and 7. Through thecenter of this plug or coupling 5 extends a hole 8 and above thecoupling 5 extend the hollow drill rods 9 commonly used in thesedrillsand by means of which the drill bit is rotated and through which.

abrading material or shot is supplied to the cutting edges of the bit orcutting tool. f

Extending from the lower end of the hole 8 and through the coupling 5are three or more` holes 10 bored radially from the central hole 8 tothe outer circumference of the lower end of the coupling 5. It will beseen from Fig. lthat these small holes 10 in connection with the hole 8and the annular space between the tubes 1 and 3 form a contlnuouspassage for the shot or other abrading material supplied to thedrillbit. This passage will be entirely within the parts of "the drill sothat none of the shot can come in contact with the core which would havethe effect of cutting away the core and also the shot are kept away fromthe outer Walls of the cutting tool which otherwise would greatlyincrease the friction and power losses of the tool as well as causelosses of the shot or abrading material through crevices in the strata.through which the drill is cuttin Norma ly closing the lower end of thehole 8 through the plug 5 is a valve 11 pressed against its seat 12formed in the plug 5 by means of a spring 13. The valve stem 14 passesthrough a hole in alinement with hole 8 in a yoke piece 15 by means ofwhich the valve 11 and spring 13 are retained in position. The spring 13is made strong enough to hold the valve 11 closed during the normaloperation of the tool and while shot is being supplied to the tool. Thevalve 11 is, however, opened by heavy pressure against it when it isused for a purpose presently to be described.

The location of the valve 11 exactly in the position above described isnot essential to my invention. This valve 11 may be equally well locatedsomewhat above the position shown. In that case the holes 10 would alsobe raised to a corresponding degree and could then be drilled tointercept the space between the core barrels at the upper edge of thecore barrel 1. This would avoid drilling hole 8 through the threadedportion of the core barrel 1.

In the operation of my improved core drill, during the normal operationor while cutting or abrading is taking place the drill 4is slowlyrotated by means of the drill rods 9 and shot or other abradiiigmaterial is supplied through the hollow drill rods and through the hole8 in the plug or coupling 5 to the annular space between the cuttingtubes 1 and 3 through which it passesto the lower ends of the tubes toabrade or 'iiit the strata through which the drill is passing. When asuiiicient length of core has been cut' to fill the core barrel withinthe tube or pipe 1 the rotation of the drill is stopped and groutingmaterial usually comprising heavy and coarse gravel is passed downthrough the drill rods 9 and then the pressure within the rods 9 andwithin the plug or coupling 5 is greatly increased by increasing thepumping of iwater into the rods 9. This forces the valve 11 to open andadmit the grouting material to the core barrel.- The grouting materialis then allowed to force its way down the inside of the tubin 1 by meansof the s ace between the tubing 1 and the core to t e lower end of thecore barrel. This action may he somewhat aided by a few partial turns ofthe cuttin tool. By this means the grouting material becomes ti htlywedged between the core and inner tul 1 when the core is broken off andas it is still tightly wedged by means of the grouting material it maybe drawn to the surface with the cutting tool.

From the above description it is thought that the construction andoperation of my improved core drill will out further explanation,

be apparent with- It is to be understood that the present showing anddescription disclose only one specific modification of my invention, andother forms and embodiments are included within the spirit and scope ofthe same as expressed in the appended claims.

lVhat I claim is:

1. In a core drill, a hollow drill bit comprising inner and outerconcentric tubes and means for supplying abrading material between saidtubes to the cutting edge of said bit.

2. In a core drill, a hollow drill bit coinprising inner and outerconcentric tubes, one of said tubes being provided with a spiralprotuberance whereby said tubes are separated and abrading material maybe supplied to said bit between said tubes.

3. In a core drill, a core barrel, a tubing surrounding said core barreland providing a passage between said outer tubing and core barrel, acutting tool on said core barrel and outer tubing adapted to useabrading inaterial and means for supplying abrading material from thesurface to said cutting tool as the cutting progresses through thepassage within the drill and outside of said core barrel.

4. In a core drill, a core barrel, a cutting tool on said core barreladapted to use abrading material and means ooperating with said corebarrel to supply abrading material from the surface to said cutting toolas the cutting progresses out of contact with the core and the wall ofthe hole being drilled.

. 5. In a core drill. inner and outer tu'bes providing abrading tools ontheir lower edges, said tubes being separated suliiciently to provide apassage for abrading material;

to pass downwardly between them to said lower edges.

6. In a core drill. a drill bit having a tube comprising a core barrel,a, tube surr0unding said core barrel, a hollow drill rod meansooperating with said drill bit for supplying abrading material throughsaid drill rod to said drill bit between said tubes, and means normallyclosing said core barrel for permitting grouting material to ass frimsaid hollow drill rod to said core bar: re

7. In a core drill, tubes providing a dou-l ble drill bit having a corebarrel provided with means for su plying abrading mate` rial between thetu es forming said doubl drill bit, a central hollow drill rod, a hollow coupling connecting said drill bit and hollow drill rod, and meansnormally clos-j ing said core barrel for permittin grouting material topass through saidI hollow` drill rod directly to said core barrel.

8. In a core drill, a. double drill bit hav ing a core barrel, a hollowdrill rod, meani coperating with said drill bit for normali:1

mensen supplying abrading material to said double dnl bit through saidhollow drill rod, a valve in said core drill normally held closed andadapted when opened to open a tissage between the hollow drill rod and te core barrel.

9. In a core drill, tubes forming a' double drill bit having a corebarrel means coperatin with seid drill bit or supplying abradingmaterial between the tubes forming said double drill bit, comprising aeentral hollow drill rod, a hollow coupling con- 'sege from the honecting said drill bit and hollow drill rod, seid parts forming apassage for normally su lying ebrading materiel through said ho ow drillrod, a, valve contained within said coupling, Suid valve adapted to beopened under heevly pressure to open a peslow drill rod to the corebarrel.

In testimony whereof I have my hand.

hereunto set FRANK MILLER.

